Invert audio filter?

[Reel.Deel]

Hi there people,

Does anyone know of a way to invert the audio in AviSynth? I have searched but came up empty handed. I'm sure it's not a common thing people do but audio editors do have a way to invert (flip) the audio.

[Dogway]

Maybe Reverse().Killvideo()?

[StainlessS]

Clarification, You mean, +ve peaks become -ve, and -ve peaks become +ve ?
Yes.
(cant help, just dont think Doggy understood)

[Reel.Deel]

Originally Posted by Dogway

Maybe Reverse().Killvideo()?

That would reverse the audio. Audio invert (also known as polarity invert, phase invert and others) is more like the filter Invert() for video. It basically flips the waveform 180 degrees.



Edit

Originally Posted by StainlessS

Clarification, You mean, +ve peaks become -ve, and -ve peaks become +ve ?

Yep.

[Dogway]

Ah yes, flip the waveform, basically you multiply the audio by -1.0. In this regard it's like amplifying negatively, Amplify() already has that built in I think. Amplify(-1) by the examples.

[StainlessS]

A=Colorbars
B=A.Amplify(-1.0)

A=A.Waveform_Filmstrip(window=1,under=true,SubSize=0.25)
B=B.Waveform_Filmstrip(window=1,under=true,SubSize=0.25)

StackVertical(A,B)

Only showing 1 (upper) channel [the other channel was silent for that colorbars frame].

Good Dog.

[Reel.Deel]

Originally Posted by Dogway

Ah yes, flip the waveform, basically you multiply the audio by -1.0. In this regard it's like amplifying negatively, Amplify() already has that built in I think. Amplify(-1) by the examples.

Dang, now I feel like a dummy. I even updated the documentation for the avs+ page . I vaguely recall reading something but I kept looking for "invert audio avisynth" and the Amplify page does not come up on Google. Thanks Dogway!